There should be a software that can be used to configure at least part of any software, with product-specific definition files that tell how to edit config files for VLC and others. This especially for key bindings. Is there? This could be meant to be common for Qt software.
Using that kind of software would be easier than editing configuration files with a text editor but have some extra steps compared to build-in configurators like VLC has.
VLC could need a button for reloading the configuration file from disk or there has to be some inter-process communication.